Piston



Dec. 1, 1936. J. 'H. DAVIS 2,062,808

PISTON Inventor aygg flgti w v Allomey 'Paten ta"'DeLU I936 f'i' u v UNITED STATES PATENT o plicatil:1 $rc l:2i ?9:; ;;l:l ;o. 88,723

2 Claims- (01. 309-36) This invention relates to an improved piston units which go to make up the rubber packing construction, having more particular reference mounting and clamping assembly. to a type which is ideally and peculiarly adapt- Figure 6 is a fragmentary end view of the mulable and useful in slush pumps such as are used iple annu a r ve ru r p i r n to maintain the circulation of flushing fluids in. Figure 7 is Derspeetive V w Of a sh m eonwell drilling operations. stituting a part of the assembly as disclosed in In the perfection and development of piston Fi u constructions in this particular classification, S sh wn better in Figure 2, the rec p o at y considerable thought has been given to the idea of pi ton r s e ed by the numeral 8 and is promoting longevity while retaining an eifective fo med wi a eve ed shou der 9 m in int 10 seal even over a prolonged period of operation. a reduced extension whose inner end is smooth Along the line of the present invention to be to provide an adapter stem as indicated at l0 hereinafter described in detail, it may be said and whose outer end is screw-threaded as inthat the art includes a sectional head 'construcdicated at H to provide a requisite shank to action embodying expanding and contractingmeans commodate the clamping nut 52 and the lock 5 or elements cooperable with an interposed ranut 3. 1 dially expansible and contractible packing an- The rubber annulus peeking ring 0 ber nulus. is indicated by the numeral I3 and is of some- It is in the foregoing particular field of imat ve on annu ar expansible and conprovement in which I have worked and finally tractible f mt is e n. w v r. as

developed what is believed to be a comparatively being prov d at it pposite ends with substannew and structurally distinct adaptation chartially conical cavities '5 in turn provided With acterized in one sense by a radially expansible concentric graduated ov There are three and contractible rubber annulus or packing ring, g the inner and Outer Ones being e v i? wherein means is located between the coordi- Shallow d denoted y the numerals l5 and |-25 nated surfaces of the ring and the clamping and and the intervening central o ein someadjusting parts to provide a substantially fiuid- What deeper and difierentia-ted by the numeral proof seal. I8. In addition, I provide peripheral circumfer- Novelty is also predicated, as will be hereinentielly'extending pa p a rooves l9 and after clarified, on an ingenious structural ar- 29 which are disposedin at in a dly 30 rangement characterized by the companion meconverging r o p as compared to each tallic parts forming the sectional mounting and other- This provides for d m of mpression clamping means for the rubber annulus wherein expansion on the P p y t generally these parts are designed for respective adjustf d in the marginal construction f su h packment to obtain more effective and lasting admg 35 justing and sealing results. The annulus is supported on or accommodated Other features and advantages will become by a two-part emblage which may be conmore readily apparent, from t following veniently definedas a mounting or hub strucscription and the accompanying illustrative e relatively Stationary n is denoted 40 drawings by the numeral 2| and the companion relatively 40 In the drawings; movable follower unit is indicated at 22. The Figure 1 is a side elevational view disclosing casting comprises cylindrical open-ended the appearance, externally, of the improved and sleeve hub proper 23 which surrounds the structurally refined piston or plunger head. smoolh stem portiorl of the piston At Figure 2 is a View partly in section and partly the right hand end is a beveled shoulder 24 in- 45} in elevation disclosing with greater particularity tlmately cooperating with the bevel-ed Shoulder the details and coordinated assemblage depicted g gg gg gg z'g z ggig g ggffig g z g in Figure 1.

D of a diameter less than the diameter of the cavity Figure 3 an end of Figure 1 bserv1ng l5 into which it fits. The entire inner face of 50 it in a direction from lef to ri the flange is beveled radially inward or outward, Figure 4 is an inside elevational or face view of as th ase may be, to form a sort or a conical the nut adjusted flanged collar or compressing clamping surface to cooperate with the correand follower disk. spondingly shaped surface of the cavity l5. In- Figure 5 is a sectional view disclosing the two cidentally. on this surface I provide integral an- 55 nular ribs or beads l6, l1, and I8 which features cooperate with the grooves l8, l1, and I8, in the rubber. The relatively long central bead fits into the correspondingly deep groove l8. These features come together in proper matching relation to provide requisite coacting means calculated to form a fluid tight seal or joint between the conical flange 25 and the conical surface of the complemental cavity IS.

The relatively slidable clamping and take-up collar or follower unit 22 is also in the nature of a disk 28 corresponding to the cavity and having the same taper as on the part 25. It is also formed with corresponding ribs to fit into the corresponding grooves in the rubber. Hence, the same numerals-designate the same parts. It is to be noted that the collar portion 21 is screwthreaded as at 28, to provide a feed nut. In addition, it is fashioned with a socket 29 to telescopically receive the left hand end of the cylindrical hub member or sleeve 23. Located in the space between the bottom of the socket and the end of the hub are the shims 30'. A suitable number of shims is introduced at the initial installation and the number of shims is gradually reduced as wear takes place and as it becomes necessary to feed the follower unit 22 into bind the special adaptation and coordination thereof.

It is thought that the description taken in connection with the drawings will enable a clear understanding of the invention to be had. Therefore, a more lengthy description is thought unnecessary.

While the preferred embodiment of the invention has been shown and described, it is to be understood that minor changes coming within the field of invention claimed may be resorted to if desired.

I claim:

1. As a new product of manufacture and as a component part of a structure of the class described, an annular compressible rubber packing ring, said ring being provided with a pair of converging peripheral grooves and having conical cavities formed in its opposite ends, said cavities being provided with concentric radially spaced grooves in the manner and for the purposes described.

2. A pump piston comprising a piston rod, a pair of telescoping hub members mounted on the rod, said hub members including flanges having bevelled opposed faces, a plurality of annular ribs formed on said opposed faces of the flanges, an annular compressible rubber packing ring positioned between said flanges and having inclined ends correspondingto the bevelled faces of the flanges and also having annular grooves in its ends to accommodate the ribs on the flanges, said ring being of greater diameter than the flange and a plurality of circumferential grooves formed on the peripheral edge of the ring having their walls inclined toward each other to provide a plurality of packing surfaces on the ring and to facilitate expansion thereof.

JACK H. DAVIS. 

